Quantitative Assessment of Low-Dose Photodynamic Therapy Effects on Diabetic Wound Healing Using Raman Spectroscopy

Area of Science:

• Biomedical Engineering
• Photomedicine
• Dermatology

Background:

• Diabetic wound healing is a significant clinical challenge due to complex molecular mechanisms.
• Delayed healing in diabetes involves numerous physiological variables.
• Low-dose photodynamic therapy (LDPDT) shows promise for tissue rejuvenation and wound healing.

Purpose of the Study:

• To investigate the efficacy of LDPDT on diabetic wound healing in a mouse model.
• To evaluate the impact of different photosensitizers (5-aminolevulinic acid, methylene blue) and laser doses (1 J/cm², 4 J/cm²).
• To develop a noninvasive method for quantitative assessment of diabetic wound healing using Raman spectroscopy.

Main Methods:

• Utilized LDPDT with two photosensitizers and two laser doses on diabetic mouse wounds.
• Employed Raman spectroscopy (RS) as a noninvasive technique to analyze tissue molecular composition.
• Developed a quantitative assessment approach using principal component analysis and Mahalanobis metrics on skin Raman spectra (Amide I and CH₂ bands).

Main Results:

• LDPDT demonstrated positive effects on diabetic wound healing.
• Raman spectroscopy provided specific molecular and structural information about the tissue state.
• The developed RS-based approach enabled in vivo quantitative assessment of wound healing progression.

Conclusions:

• LDPDT is a promising therapeutic strategy for accelerating diabetic wound healing.
• Raman spectroscopy offers a valuable noninvasive tool for monitoring wound healing.
• Quantitative analysis of Raman spectra can effectively assess the in vivo state of diabetic wound healing.